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Introduction: The presence of low‐voltage zones (LVZs) in the left atrium (LA) is associated with the recurrence of atrial fibrillation (AF) following pulmonary vein isolation (PVI). However, there is variability and conflict in the data regarding predictors of LVZs as reported in previous studies. The objective of this study was to identify predictors for the presence of LVZs in a cohort of patients with persistent AF. Methods: The study prospectively enrolled 439 patients with persistent AF who were scheduled for ablation. Voltage map of the LA was collected using a multipolar catheter. An LVZ was defined as an area of ≥3 cm2 exhibiting a peak‐to‐peak bipolar voltage of <0.5 mV. Results: The mean age of the cohort was 65.3 ± 8.6 years and 26.4% were female. Additionally, 25.7% had significant LVZs, most frequently located in the anterior wall of the LA. Multivariable analysis identified the following independent predictors for LVZ: advanced age (OR [odds ratio] = 1.08, 95% CI [confidence interval] = 1.03–1.13, p =.002); female sex (OR = 4.83, 95% CI = 2.66–8.76, p <.001); coronary artery disease (CAD) (OR = 3.20, 95% CI = 1.32–7.77, p =.01) and enlarged LA diameter (OR = 1.10, 95% CI = 1.04–1.17, p =.001). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the final model was 0.829. Conclusion: Approximately 25% of the patients with persistent AF had LVZs. Advanced age, female sex, CAD, and a larger LA were independent predictors for LVZs with the model demonstrating a very good AUC for the ROC curve. These findings hold the potential to be used to tailor the ablation procedure for the individual patient. [ABSTRACT FROM AUTHOR]

BackgroundObesity is a risk factor for atrial fibrillation (AF). Data regarding left atrial (LA) remodeling in obese patients are scarce. Whether obesity favors AF recurrence after catheter ablation (CA) is still controversial. We assessed the distribution of epicardial atrial fat on computed tomography (CT), LA bipolar voltage, low-voltage zone (LVZ) extent, and the outcome of voltage-guided ablation of persistent AF in obese and non-obese patients.MethodsA total of 139 patients with persistent AF undergoing a first voltage-guided ablation were enrolled and divided into two groups: 74 were non-obese and 65 were obese. Epicardial adipose tissue (EAT) was assessed on a CT scanner. LA endocardial voltage maps were obtained using a 3D mapping system in sinus rhythm. LVZ was defined as a bipolar peak-to-peak voltage amplitude

BackgroundGender-related differences have been reported in atrial fibrotic remodeling and prognosis of atrial fibrillation (AF) patients after ablation. We assessed in persistent AF the regional distribution of left atrial (LA) bipolar voltage and the extent of low-voltage zones (LVZ) according to gender as well as the results of a voltage-guided substrate ablation.MethodsConsecutive patients who underwent a voltage-guided AF ablation were enrolled. LA endocardial voltage maps were obtained using a 3D electro-anatomical mapping system in sinus rhythm. LVZ was defined as

Background: Low-voltage zones (LVZ) are surrogate markers for cardiac fibrosis, which contribute to the maintenance of atrial fibrillation (AF). The aim of this study was to investigate the effect of the distribution of left atrial (LA) LVZ on the outcome following catheter ablation. Methods: This retrospective study enrolled patients with AF who underwent initial catheter ablation. LVZ were defined as areas with bipolar voltage amplitude 30 s after the initial catheter ablation. Results: Altogether, 148 patients were included, with a mean age of 61 ± 11 years, of which 53 (35.8%) had persistent AF. During a mean follow-up of 14 ± 3 months post-ablation, AA recurrence occurred in 25 (16.9%) patients after the initial catheter ablation. Kaplan–Meier analysis showed that patients without roof LVZ had a higher AA-free survival rate than those with roof LVZ (P = 0.047). In the multivariate Cox regression analysis, the proportion of LA LVZ ≥6% [hazard ratio (HR) 2.315, 95% confidence interval (CI) 1.048–5.114; P = 0.038] and a longer AF duration (HR 1.008, 95% CI 1.002–1.014; P = 0.006) were independent predictors of AA recurrence. Conclusions: In patients with AF, LA roof LVZ may increase the risk of AA recurrence after initial catheter ablation.

Background Left atrial substrate may have mechanistic relevance for ablation of atrial fibrillation (AF). We sought to analyze the relationship between low‐voltage zones (LVZs), transition zones, and AF recurrence in patients undergoing pulmonary vein isolation. Methods and Results We conducted a prospective multicenter study on consecutive patients undergoing pulmonary vein isolation‐only approach. LVZs and transition zones (0.5–1 mV) were analyzed offline on high‐density electroanatomical maps collected before pulmonary vein isolation. Overall, 262 patients (61±11 years, 31% female) with paroxysmal (130 pts) or persistent (132 pts) AF were included. After 28 months of follow‐up, 73 (28%) patients experienced recurrence. An extension of more than 5% LVZ in paroxysmal AF and more than 15% in persistent AF was associated with recurrence (hazard ratio [HR], 4.4 [95% CI, 2.0–9.8], P

Background: Although low‐voltage zones (LVZs) in the left atrium (LA) are considered arrhythmogenic substrates in some patients with atrial fibrillation (AF), the pathophysiologic factors responsible for LVZ formations remain unclear. Objective: To elucidate the anatomical relationship between the LA and ascending aorta responsible for anterior LA wall remodeling. Methods: We assessed the relationship between existence of LVZs on the anterior LA wall and the three‐dimensional computed tomography image measurements in 102 patients who underwent AF ablation. Results: Twenty‐nine patients (28%) had LVZs grearer than 1.0 cm2 on the LA wall in the LA‐ascending aorta contact area (LVZ group); no LVZs were seen in the other 73 patients (no‐LVZ group). The LVZ group (vs. no‐LVZ group) had a smaller aorta‐LA angle (21.0 ± 7.7° vs. 24.9 ± 7.1°, p =.015), greater aorta‐left‐ventricle (LV) angle (131.3 ± 8.8° vs. 126.0 ± 7.9°; p =.005), greater diameter of the noncoronary cusp (NCC; 20.4 ± 2.2 vs. 19.3 ± 2.5 mm; p =.036), thinner LA wall‐thickness adjacent to the NCC (2.3 ± 0.7 vs. 2.8 ± 0.8 mm; p =.006), and greater cardiothoracic ratio (percentage of the area in the thoracic area, 40.1 ± 7.1% vs. 35.4 ± 5.7%, p <.001). The aorta‐LA angle correlated positively with the patients' body mass index (BMI), and the aorta‐LV angle correlated negatively with the body weight and BMI. Conclusion: Deviation of the ascending aorta's course and distention of the NCC appear to be related to the development of LA anterior wall LVZs in the LA‐ascending aorta contact area. Mechanical pressure exerted by extracardiac structures on the LA along with the limited thoracic space may contribute to the development of LVZs associated with AF. [ABSTRACT FROM AUTHOR]

Background: Obesity is a risk factor for atrial fibrillation (AF). Data regarding left atrial (LA) remodeling in obese patients are scarce. Whether obesity favors AF recurrence after catheter ablation (CA) is still controversial. We assessed the distribution of epicardial atrial fat on computed tomography (CT), LA bipolar voltage, low-voltage zone (LVZ) extent, and the outcome of voltage-guided ablation of persistent AF in obese and non-obese patients., Methods: A total of 139 patients with persistent AF undergoing a first voltage-guided ablation were enrolled and divided into two groups: 74 were non-obese and 65 were obese. Epicardial adipose tissue (EAT) was assessed on a CT scanner. LA endocardial voltage maps were obtained using a 3D mapping system in sinus rhythm. LVZ was defined as a bipolar peak-to-peak voltage amplitude <0.5 mV., Results: LA volume, voltage, and EAT amount were similar in the two groups. LVZ was less frequent in obese patients [12 (18.8%) vs. 26 (35.1%), p  = 0.05], particularly on the anterior wall. The posterior and lateral EATs were correlated with posterior and lateral LVZ extent, respectively, in obese patients. After 36 months of follow-up, the AF-free survival rate was similar. Lateral EAT [odds ratio (OR) 1.21, 95% confidence interval (CI) 1-1.4, p  = 0.04] and P-wave duration (OR 1.03, 95% CI 1-1.05, p  = 0.03), but not body mass index (BMI), were predictors of AF recurrence after CA., Conclusion: In obese patients, LVZ was less marked than in non-obese patients with similar LA volumes, voltage, and EAT amounts. In obese patients, posterior and lateral EATs were correlated with posterior and lateral LVZ extents. Obese patients had a similar and favorable 36-month outcome after AF ablation. BMI was not predictive of AF recurrence., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Marzak, Fitouchi, Labani, Hammann, Ringele, Kanso, Cardi, Schatz, Ohlmann, Morel and Jesel.)

Inflammation has been suggested to play a key role in the pathogenesis of atrial fibrillation (AF). Our hypothesis was that this inflammation, mediated by intermediate monocytes and toll-like receptor 4 (TLR4), causes the formation and expansion of low-voltage zones (LVZs). Prior to ablation, the monocyte subsets of 78 AF patients and TLR4 expression of 66 AF patients were analyzed via a flow cytometric analysis. Based on the CD14/CD16 expression, the monocytes were divided into three subsets: classical, intermediate, and non-classical. At the beginning of the ablation session, voltage mapping was performed. LVZs were defined as all bipolar electrogram amplitudes of < 0.5 mV. Correlations between the flow cytometric analysis results and presence of LVZs, as well as the total area of the LVZ, were examined. Patients with LVZs clearly had a higher proportion of intermediate monocytes (10.0 ± 3.6% vs. 7.2 ± 2.7%, p < 0.001) than those without LVZs. TLR4 was much more frequently expressed in the intermediate monocytes than other two monocyte subsets (p < 0.001). Moreover, the TLR4 expression level in intermediate monocytes correlated positively with the total area of the LVZs (r = 0.267, p = 0.030), especially in patients with paroxysmal AF (r = 0.365, p = 0.015). The intermediate monocytes and TLR4 expression positively correlated with LVZs in AF patients. [ABSTRACT FROM AUTHOR]

Background: Gender-related differences have been reported in atrial fibrotic remodeling and prognosis of atrial fibrillation (AF) patients after ablation. We assessed in persistent AF the regional distribution of left atrial (LA) bipolar voltage and the extent of low-voltage zones (LVZ) according to gender as well as the results of a voltage-guided substrate ablation., Methods: Consecutive patients who underwent a voltage-guided AF ablation were enrolled. LA endocardial voltage maps were obtained using a 3D electro-anatomical mapping system in sinus rhythm. LVZ was defined as <0.5 mV., Results: A total of 115 patients were enrolled (74 men, 41 women). The LA bipolar voltage amplitude was twice lower in the whole LA ( p  < 0.01) and in each atrial region in women compared with men, whereas the LA indexed volume was similar. LVZ were found in 56.1% of women and 16.2% of men ( p  < 0.01). LVZ were also more extensive in women ( p  = 0.01), especially in the anterior LA. Atrial voltage alteration occurred earlier in women than in men. In a multivariate analysis, the female sex (OR 12.99; 95% CI, 3.23-51.63, p  = 0.0001) and LA indexed volume (OR 1.09; 95% CI, 1.04-1.16, p  = 0.001) were predictive of LVZ. Atrial arrhythmia-free survival was similar in men and women 36 months after a single ablation procedure., Conclusion: The study reports a strong relationship between the female gender and atrial substrate remodeling. The female gender was significantly associated with higher incidence, earlier occurrence, and greater extent of LVZ compared with men. Despite the female-specific characteristics in atrial remodeling, LVZ-guided ablation may improve the AF ablation outcome in women., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Marzak, Ringele, Matsushita, Marchandot, Fitouchi, Cardi, Kanso, Schatz, Hammann, Ohlmann, Morel and Jesel.)

Background Left atrial substrate may have mechanistic relevance for ablation of atrial fibrillation (AF). We sought to analyze the relationship between low-voltage zones (LVZs), transition zones, and AF recurrence in patients undergoing pulmonary vein isolation. Methods and Results We conducted a prospective multicenter study on consecutive patients undergoing pulmonary vein isolation-only approach. LVZs and transition zones (0.5-1 mV) were analyzed offline on high-density electroanatomical maps collected before pulmonary vein isolation. Overall, 262 patients (61±11 years, 31% female) with paroxysmal (130 pts) or persistent (132 pts) AF were included. After 28 months of follow-up, 73 (28%) patients experienced recurrence. An extension of more than 5% LVZ in paroxysmal AF and more than 15% in persistent AF was associated with recurrence (hazard ratio [HR], 4.4 [95% CI, 2.0-9.8], P <0.001 and HR, 1.9 [95% CI, 1.1-3.7], P =0.04, respectively). Significant association was found between LVZs and transition zones and between LVZs and left atrial volume index (LAVI) (both P <0.001). Thirty percent of patients had significantly increased LAVI without LVZs. Eight percent of patients had LVZs despite normal LAVI. Older age, female sex, oncological history, and increased AF recurrence characterized the latter subgroup. Conclusions In patients undergoing first pulmonary vein isolation, the impact of LVZs on outcomes occurs with lower burden in paroxysmal than persistent AF, suggesting that not all LVZs have equal prognostic implications. A proportional area of moderately decreased voltages accompanies LVZs, suggesting a continuous substrate instead of the dichotomous division of healthy or diseased tissue. LAVI generally correlates with LVZs, but a small subgroup of patients may present with disproportionate atrial remodeling, despite normal LAVI.

Background: Low-voltage zones (LVZ) are surrogate markers for cardiac fibrosis, which contribute to the maintenance of atrial fibrillation (AF). The aim of this study was to investigate the effect of the distribution of left atrial (LA) LVZ on the outcome following catheter ablation., Methods: This retrospective study enrolled patients with AF who underwent initial catheter ablation. LVZ were defined as areas with bipolar voltage amplitude <0.5 mV. The left atrium was divided into six regions (anterior wall, roof, posterior wall, lateral wall, septum, and inferior wall) to describe the distribution of LVZ. The primary endpoint was atrial arrhythmia (AA) recurrence lasting >30 s after the initial catheter ablation., Results: Altogether, 148 patients were included, with a mean age of 61 ± 11 years, of which 53 (35.8%) had persistent AF. During a mean follow-up of 14 ± 3 months post-ablation, AA recurrence occurred in 25 (16.9%) patients after the initial catheter ablation. Kaplan-Meier analysis showed that patients without roof LVZ had a higher AA-free survival rate than those with roof LVZ (P = 0.047). In the multivariate Cox regression analysis, the proportion of LA LVZ ≥6% [hazard ratio (HR) 2.315, 95% confidence interval (CI) 1.048-5.114; P = 0.038] and a longer AF duration (HR 1.008, 95% CI 1.002-1.014; P = 0.006) were independent predictors of AA recurrence., Conclusions: In patients with AF, LA roof LVZ may increase the risk of AA recurrence after initial catheter ablation., (Copyright © 2022 Hellenic Society of Cardiology. Published by Elsevier B.V. All rights reserved.)